INFUSORIAL ANIMALCULES. 



31 



tinctly discerned fringing its surface. Within the globe a number of smalkr 

 globes are perceived ; and these lead us to consider the extraordinary manner in 

 which these curious groups are multiplied. They increase by a voluntary separa- 

 tion: from time to time new spherical clusters are thrown off from the original globe; 

 not, however, from its outer surface, into the surrounding water, but from the inner 

 surface, into the space enclosed by the transparent shell. Six or eight of these 

 spherical groups are usually found within the parent globe ; though, at times, 

 as many as twenty have been seen at once, with their forms well defined, and 

 their color of a bright green. Openings exist, both in the primary sphere and 

 in the interior globes, through which water passes and repasses for the purpose 

 of affording the animalcules fresh supplies of air and food. As the young globes 

 increase in size, the surrounding envelope expands, and as soon as they have 

 attained a certain degree of maturity, it bursts asunder and permits them to 

 escape. Now, uncontrolled in their motions, they range through a wider field 

 of existence, and soon a new generation of revolving monads issues from their 

 parting spheres ; to become, in their turn, the parents of other globes, and so on 

 in a countless series. 



Fig. 1! 



This process of increase is exhibited in figure 15, where 

 the offspring are shown issuing from the parent sphere, and 

 within each of the smaller globes another incipient race of re- 

 volving animalcules is detected. The full sized globes are 

 one-thirtieth of an inch in diameter, and the size of the small- 

 est, when liberated from the parent, is one-three hundred and 

 sixtieth of an inch. 



In figure 16, is delineated a portion of a globe with 

 five single animalcules and a cluster of six young 

 ones at a; they are all attached to the spherical case, and 

 to each other, and the bands which connect them 

 together, as well as their respective organs of motion, 

 are distinctly seen. 



In figure 1 7, a single monad of a revolving globe, sepa- 

 rated from its case, is magnified two thousand times ; or, 

 in other words, covers upon the paper a space four mil- 

 lion times greater than its natural extent. In this 

 engraving, the two cilia are seen at 6, 6, the six uniting 

 threads at c, c, c, c, c, c, and the eye of the animalcule, 

 which is of a bright red, is situated at d. The natural 

 size of a single animalcule, is the thirty-Jive hundredth 

 part of an inch. The revolving globe is a common spe- 

 cies of Infusoria, and is easily found in the clear shallow 

 waters of brooks and ponds. 



Fig. 17. 



